The 31-year-old Rodriguez equaled the 14 home runs hit by St. Louis Cardinals first baseman Albert Pujols, who accomplished the feat in April 2006.
Rodriguez is in his fourth season with the Yankees and, he says, his most comfortable. Rodriguez has spoken often about feeling that he has been in a "good place" from the first day of Spring Training in Tampa, Fla., though there have been physical adjustments, as well.
Rodriguez made great efforts to trim his body weight and fat over the offseason, and hitting coach Kevin Long has tinkered with his swing, making it shorter to the ball and more compact.
"I definitely feel a bit more athletic, and I feel younger," Rodriguez said.
The torrid beginning to Rodriguez's season has prompted some to question if, given his head start, he could challenge Barry Bonds' single-season record of 73 home runs.
"If he stays healthy, I don't know what the limit would be for him," said Yankees manager Joe Torre. "He's very talented, and he's gifted. He doesn't take his ability for granted -- he's out there working every day and trying to keep himself ready to play."
A-Rod finished one RBI shy of Juan Gonzalez's Major League record for most RBIs hit in April, set in 1998 with the Texas Rangers. Gonzalez drove in 35 runs that month.
Rodriguez had his final shot at that record in the eighth inning of New York's 7-4 loss to Boston on Sunday afternoon, but Mike Timlin induced Rodriguez to hit into an inning-ending double play.
Rodriguez, who has outhomered five Major League teams through Sunday's action, became the first Yankees player to have as many as 14 home runs and 34 RBIs in a single calendar month since June 1961, when Roger Maris collected 15 home runs and 35 RBIs.
The accomplishments would be a lot more enjoyable for Rodriguez, however, if the team would resume its winning ways. The Yankees have lost eight of their last nine games and look to right the ship on Tuesday at Texas -- a place familiar to Rodriguez -- as a new month begins for both A-Rod and the Yankees.
Rodriguez signed a 10-year, $252 million contract with the Texas Rangers before the 2001 season and was traded to the Yankees prior to the 2004 season.
"Once we get on a roll, I think we're going to be fine," Rodriguez said. "The things to start worrying about this month is winning two out of three, three out of four. Small bites and small steps."